For exascale computing, massive reduction in the energy used to transport data to and from memory and between processors, along with a commensurate increase in the amount of data per fiber, may enable devices that are manageable in power consumption and in the number of fiber interconnections. Solutions being developed to accomplish this include low power vertical cavity surface emitting lasers (VCSELs), silicon-bonded edge emitting lasers and external modulation technology utilizing silicon photonics.
Silicon photonics, for example, offer wavelength division multiplexing (WDM) capability integrated into the chip stack and may be compatible with legacy silicon foundries. In addition, with silicon photonics, a laser source may be provided separate from the chip, thus allowing the chip to be isolated from heat produced by the laser source. Low power silicon photonics, however, typically rely on resonators that may be sensitive to local temperature swings. Thus, a resonance frequency of silicon-based resonators may shift with variation in temperature.